As shown in FIG. 49, Patent Document 1 discloses a force-moment sensor 103 comprising a first member 100 and a second member 101 provided as a pair of opposed circular plates; annular bridge elements 102 connecting the first and second members 100 and 101 to each other; and a strain gauge attached to each bridge element 102.
In the sensor 103, each bridge element 102 is disposed perpendicularly to the first and second members 100 and 101. A strain gauge is attached with an adhesive to the outer circumferential surface of each bridge element 102 or the inner surface of a hole 104. A force or moment applied between the first and second members 100 and 101 is calculated by detecting the direction and magnitude of the strain of the annular shape of each bridge element 102 caused by the force or moment.
Patent Document: JP-A-63-78032 (FIG. 1; page 5, lower right column, line 12 to page 6, upper left column, line 14; and page 7, upper left column, line 20 to upper right column, line 12)